Governor Christie speaking Wednesday at the ribbon-cutting for Teachers Village in Newark.

Governor Christie joined Newark Mayor Cory Booker — the Democrat running for U.S. Senate and the biggest name backing the governor’s opponent for re­elec­tion — to celebrate the building of a mixed development of charter schools, retail and housing.

Christie, a Republican seeking a second term, has pressed for more charter schools and for vouchers as a solution to failing public schools in New Jersey, particularly in struggling cities such as Newark.

Barbara Buono at a Tuesday event in New Brunswick. She spoke to a Teamsters group on Wednesday.

On Wednesday, Christie called the new Teachers Village development in downtown Newark, built with roughly $100 million in state and federal tax credits, a “great place that will dramatically improve the education of our children, which I think we are all here to celebrate.

“For everybody here who has had a part in this, congratulations, it’s a great day for the city of Newark, and when it’s a great day for Newark, it’s a great day for New Jersey,” Christie said.

But despite the support of Booker, Democratic gubernatorial candidate Barbara Buono took a firm stance against charter schools and vouchers during her own event Wednesday.

Buono, a longtime state senator from Middlesex County running with the support of the New Jersey Education Association, the state’s largest teachers union, was asked about Christie’s push for education changes during a campaign stop at Karnak Corp., a Clark-based manufacturer of roof coatings.

“We need a governor who understands education is not just an expense, it’s an investment,” Buono said.

She said charter schools and vouchers siphon funds away from public schools, and she accused Christie of not fully funding the state’s school aid formula. For each dollar school districts don’t get from the state, Buono said they turn to overburdened property taxpayers to make up the difference.

She also knocked Christie for awarding huge tax incentives to big corporations and not the state’s small businesses.

“A budget is about priorities,” Buono said to a group of Teamsters at the manufacturing facility.

The stark difference between Buono’s and Christie’s positions when it comes to education policies and school funding illustrates a political shift in New Jersey, where candidates used to vie for the support of the powerful teachers union.

While Buono has courted and received the union’s support, Christie has openly clashed with the union and has pressed for a series of policy changes, including a successful rewriting of tenure rules.

A survey released this week from Quinnipiac University had the governor leading Buono by more than 30 points; he has a 67 percent approval rating.

The charter school issue, however, is one where public sentiment in New Jersey seems to be divided. A 2011 poll conducted by Rutgers-Eagleton found voters werenearly evenly split on charter schools, with 44 percent in favor and 42 percent against. And support surgedto more than 50 percent among black voters.

That could help explain Booker’s position on an issue where he is more closely aligned with the Republican governor than Buono. Booker, a Democrat, is running for the U.S. Senate in the special election next month that was scheduledafter Frank Lautenberg’s death in June.

“What we have built together are not simply schools,” Booker said at the event Wednesday. “We have built cathedrals of education. This should not be the exception.”

“If we stay fast to the goals before us to make America truly free, then we must continue in the commitment to not make this the exception, but together we must make this the rule,” he said.

Booker also explained how he can support Buono’s candidacy while working with Christie.

“What the people really want is not more politics,” Booker said. “What they really want, is they want people working together to get things done.”

“So right now we’re getting things done,” he said.

Booker added, “when my election is over I’ll be working hard” for Buono.